I have had them in my cupboard planning to use them to replace my old ZWO rings but have not got them setup on a dovetail bar yet. You would need to mount them on a top rail or bar. Your welcome to use them. If i had known earlier today i could have sent them to Brisbane by plane when my son flew back there this evening. PM me if you want them. I don't want to sell them but happy to lend them to you for no cost, well maybe postage.